I Lack Faith In Humanity

I have lost so many people who I thought were my true friends this year. It turns out they are just self-centred, selfish and arrogant.
I find it so difficult to keep telling myself that I am not the one with the problem, when my boyfriend, bestfriend and a couple other 'friends' let me down and shat on my head.
The man who I thought was the love of my life made moves on me 2 days ago, yet tells me today that he doesn't want anything to do with me?! He used me to his advantage.
I keep getting my heart broken and the pain is unbearable